Hideaway, I read your post before and thought you would get a respnse by now. Usually if no one responds, like me, nobody knows for sure. I could give you my educated guess though.
I would say the horns are located in the same spot regardless if it's a 6 or 8 cylinder car. As for the wiring, which I'm kind of a retard about, you should have a horn relay on the radiator support, right? Did the harness have the wires for that? It's hard for me to help if I'm not standing there looking at it. What I would try is this. Hook everything up as it will normally, then extend the green wire to the horn to see if it will work. You don't know if it is the correct wire that someone has cut for whatever reason. If that doesn't work, unwrap the light harness were it goes across radiator support to see if they have cut and wrapped up the wires for the horn there.
I have a mystery wire on my car that still drives me nuts. I rewrapped and fixed my harness after the wreck it was in. Hooked everything up, and everything works perfectly, and it's an RS to boot. Well, on the pass. side, by the battery there's a tan colored wire that's hot all the time, that goes nowhere. I can't find a place for this wire anywhere, and everything is working good and it is a factory wire in the harness to the firewall plug. It just drives me nuts sometimes.
Try these things and repost, I hope you get this figured out.
67 SS 396,4-sp
67 RS 327,4-sp
72 RS 350/350
69 4X4 suburban 350,4-sp
73 3/4 ton 454/400
Stevo Camaro's Toy
Our Muscle Cars